U.S. Pat. No. 4,160,974, which issued to the present inventor and assignee on July 10, 1979, set forth the desirability of providing a target seeker and homing sensor which is low cost, lightweight, and capable of detecting the presence and direction of a discrete target, such as a tank. The target-seeking system of the patent was suitable for use in a mini-drone aircraft. Information from radar detectors mounted in the aircraft searched for targets and, upon detection, provided guidance signals to steer the aircraft into the target.
Although the prior patent operates satisfactorily in a number of strategic situations, it has been found that armored vehicles, such as an armored tank, have most resistance to projectiles fired at their front and sides. The top of a tank is usually least armored. As a result, destruction of such a target is most likely if a ballistic body could be fired directly at the top surface of the tank. An existing armament consists of a self-forging fragment which has an extremely high kinetic energy and has demonstrated the capability to penetrate heavy armor. By improving the system of the mentioned patent, an effective weapon control system results which permits maximum utilization of a self-forging fragment. In a preferred embodiment of the invention, a projectile is fired over a target tank so that the projectile passes over it at an altitude typically between 50 feet-200 feet. Normally, such a round is spinning at several hundred revolutions per second, the spin being imparted by the gun barrel rifling. For this invention, the spin is a non-permissible condition and, therefore, means are provided to reduce the spin to zero prior to firing of the projectile contained self-forging fragment. The inventive sensor consists of a radar, preferably operating as a millimeter wave radar having a distinctive antenna pattern and which will perform the functions of determining the spin rate of the projectile, the approximate vertical direction, detection of the target, measurement of range and direction to the target and providing the detonating signal to fire a self-forging fragment at an appropriate time.